Web Services are business processes that can be discovered, accessed and automatically executed over the Internet using standard protocols. By using web services, a remote, service-providing application (the “provider”) can be readily connected to a client application (the “consumer”) using standard data formats and standard Internet protocols. Web services can interconnect applications that use completely different hardware platforms, such as mainframes, application servers, and web servers, and support connections among disparate operating systems such as Windows™, Java™, and Unix™. Web services enable developers to build e-business applications that can connect with any customer, supplier, and business partner anywhere in the world, regardless of the chosen platform or programming language.
Recently introduced industry standards have helped define, at least initially, the form that web services will most commonly take. XML (Extended Markup Language) provides a cross-platform standard format for encoding and formatting data. SOAP (Simple Object Access Protocol) specifies a lightweight protocol for exchange of the information in a decentralized, distributed environment using XML, eliminating the need to share a common program language or operating system. WSDL (Web Services Description Language) is an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information. Finally, UDDI (Universal Description, Discovery and Integration) defines the operation of web-based registries that expose information about a business or other entity and its technical interfaces (or API's).
These standards play an important role in implementing and executing web services, but they do not provide any mechanism for defining and supporting the business relationships between the providers and consumers of web services. Because web service providers will typically need to derive revenue from the web services they provide if those services are to remain viable, there is a need for a mechanism by which business relationships between service vendors and service consumers can be more easily defined and implemented. Although UDDI and WSDL provide standards which service providers may use to publish descriptions of their services that consumers can in turn use to identify and connect to desired services, these standards do not provide mechanisms for defining or implementing a business relationship between providers and consumers.